Transistor is a KDE app in the works by the same developer who makes the Advanced Radio Player widget. It’s still in the early stages and I’ve no idea about mobile plans (the fact it states ‘Adaptive application layout, compatible for small and large screens’ would lead me to believe small screens means phone screens), but it functions much the same as Shortwave and has access to 50k+ stations.
If you want to test it/use it you will need to build it yourself from source.